ES2764743T3 - Three-dimensional printing apparatus and its control procedure - Google Patents

Abstract

A three-dimensional printing apparatus (100), comprising: a printing module (120), comprising: a melting nozzle (121), configured to melt a first forming material (20a) having a first color and a second forming material (20b) having a second color; and a feed module (123), configured to feed the first forming material (20a) and the second forming material (20b) to the melt nozzle in a period of filament extrusion; and characterized in that said three-dimensional printing apparatus further comprises: a controller (130), coupled to the printing module (120), and configured to: determine a first back extraction amount and a second back extraction amount in accordance with a first feed ratio of the first forming material (20a) and a second feeding ratio of the second forming material (20b) in a suspension period of filament extrusion of the printing module (120); control the feed module (123) to draw back the first forming material (20a) in accordance with the first amount of back draw along a direction (D2) away from the melt nozzle (121) in the period of filament extrusion slurry, and control the feed module (123) to back-extract the second forming material (20b) according to the second back-extraction amount along the direction (D2) away from the die (121 ) melt in the suspension period of filament extrusion, in which a sum of the first feed ratio and the second feed ratio satisfies a preset percentage, wherein said first feed ratio is the ratio of the amount of feed of the first forming material to a total feed quantity of the melting nozzle and said second feed quantity is the ratio of the feed quantity of the second mater ial of formation to the total feed amount of the melting nozzle.

Description

DESCRIPTION

Three-dimensional printing apparatus and its control procedure

Background

Technical field

The present disclosure relates to a printing apparatus and, in particular, to a three-dimensional printing apparatus and a method for controlling it.

Description of the related art

With the advancement of Computer Aided Manufacturing (Computer Aided Manufacturing, CAM), the manufacturing industry has developed three-dimensional printing technologies, which can quickly manufacture original design concepts. Three-dimensional printing technologies are actually a collective name for a number of Rapid Prototyping (RP) technologies, and the basic principles of them are all laminate manufacturing, i.e. a rapid prototyping machine. forms a cross-sectional conformation of a workpiece into a scan shape within an XY plane, and discontinuously shifts a layer thickness in Z coordinates, ultimately forming a three-dimensional object. Three-dimensional printing technologies do not limit geometric shapes, and complicated parts indicate excellence of RP technologies, that is, labor and processing time are greatly saved; and under a requirement to save most time, a digital three-dimensional model designed by 3D computer aided design software (Computer Aided Design, CAD) is actually presented.

Currently, most three-dimensional printing apparatus that forms three-dimensional objects using the above rapid prototyping procedures transport hot-melt forming materials to a nozzle using a feed mechanism, and heat and melt the forming materials by means of a feed material heating structure and nozzle, and coat them on a platform layer by layer to form a three-dimensional object. In consideration of three-dimensional print quality, to prevent redundant forming materials from dripping from a nozzle in an extrusion stop period, a three-dimensional printing apparatus slightly removes the nozzle-forming materials in an extrusion suspension period filament. In the other aspect, to increase the viability of the 3D printing apparatus and diversity of 3D printing objects, a function capable of printing a 3D object with multiple colors is also one of the focus of research and development of people. By mixing, in the nozzle, molten forming materials with two different colors, the nozzle of the three-dimensional printing apparatus can coat a forming material with a harmonious color on a platform. However, if the same amounts of two forming materials are removed from the same nozzle in the filament extrusion suspension period, when the three-dimensional printing apparatus performs printing again and continues to feed the two forming materials into the nozzle again, a harmonious color of a forming material extruded by the nozzle is different from that expected. Accordingly, there is a gap between the printed 3D object and the actual expectation, and therefore the print quality and printing performance of the 3D printing apparatus is reduced.

US 20140070461 A1 refers to a three-dimensional printer with color-switching techniques. By reversing the direction of a first building material fed into an extruder, the first building material can be completely or partially evacuated from the extruder before introducing a second material.

Summary

In view of the foregoing, the present disclosure provides a three-dimensional printing apparatus and a control method thereof, in such a way as to respectively determine, according to the feed ratios of different forming materials, amounts of back extraction by which the Forming materials are back extracted from a nozzle, thereby maintaining the consistency between harmonious colors of forming materials extruded by the nozzle.

The present disclosure provides a three-dimensional printing apparatus, which includes a platform having a support surface, a printing module, and a controller. The printing module is arranged on the platform, and includes a fusing nozzle and a feeding module. The melting nozzle is configured to melt a first forming material having a first color and a second forming material having a second color; and the feed module is configured to feed the first forming material and the second forming material to the melt die in a period of filament extrusion. The driver is attached to the print module. The controller determines a first amount of back extraction according to a first feed rate of the first forming material and determines a second amount of back extraction according to a second feed rate of the second forming material in a period of filament extrusion suspension. the print module. The controller controls the feed to feed back the first forming material according to the first amount of feed back along a direction away from the melting nozzle in the filament extrusion suspension period, and control the feed module to feed back the second forming material according to the second amount of back-extraction along the direction away from the melting nozzle in the suspension period of filament extrusion. A sum of the first feed ratio and the second feed ratio satisfies a preset percentage. The first feed ratio is the ratio of the feed amount of the first forming material to a total feed amount of the melt nozzle, and the second feed amount is the ratio of the feed amount of the second feed material to the total feed amount of the fusion nozzle.

From another point of view, the present disclosure provides a method of controlling a three-dimensional printing apparatus. The three-dimensional printing apparatus includes a fusing nozzle and a feed module. The procedure includes the following steps: When operating in a filament extrusion period, the feed module is controlled to feed a first forming material and a second forming material to the melt nozzle in such a way as to drive the nozzle melting to extrude a third forming material generated by mixing the first forming material and the second forming material; a first back extraction amount is determined according to a first feed ratio of the first forming material, and a second back extraction amount is determined according to a second feed ratio of the second forming material; and when operating in a filament extrusion suspension period, the feed module is controlled to back-extract the first forming material according to the first amount of back-extraction along a direction away from the melting nozzle, and the feed module is controlled to back-extract the second forming material in accordance with the second amount of back-extraction along the direction away from the melting nozzle, and the melting nozzle is actuated to leave a final location of Print. A sum of the first feed ratio and the second feed ratio satisfies a preset percentage. The first feed ratio is the ratio of the feed amount of the first forming material to a total feed amount of the melt nozzle and the second feed amount is the ratio of the feed amount of the second forming material to the total feed amount of the fusion nozzle.

Based on the above, in embodiments of the present disclosure, a first amount of back extraction of a first forming material is determined according to a first feed ratio of the first forming material, and a second amount of back extraction of a first forming material is determined. second forming material according to a second feed ratio of the second forming material. When the three-dimensional printing apparatus operates in a period of filament extrusion suspension, the feed module retro-extracts the first forming material according to the first amount of back-extraction along a direction away from the melting nozzle and back-extracts the second forming material according to the second back-extraction amount along the direction away from the melting nozzle. Thus, by adaptively adjusting individual amounts of back extraction from different forming materials, when the three-dimensional printing apparatus operates in a filament extrusion period again, a color of a third forming material generated in the melting nozzle by mixing the first forming material and the second forming material can maintain consistency such that the three-dimensional printing apparatus is prevented from printing a three-dimensional printed object with a non-uniform color.

Brief description of the drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

Fig. 1 is a schematic block diagram of a working situation of a three-dimensional printing apparatus according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram of a three-dimensional printing apparatus according to an embodiment of the present disclosure.

Fig. 3A and Fig. 3B are schematic diagrams of a fusion nozzle and a feed module according to an embodiment of the present disclosure.

Fig. 4 is a schematic diagram of a method for controlling a three-dimensional printing apparatus in accordance with an embodiment of the present disclosure.

FIG. 5A is an exemplary schematic diagram of back extraction amount determination according to one embodiment of the present disclosure.

Fig. 5B is an exemplary schematic diagram of back extraction amount determination according to an embodiment of the present disclosure.

Description of the embodiments

Reference will now be made in detail to the present preferred embodiments of the disclosure, the examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers are used in the drawings and the description to refer to the same or similar parts.

Fig. 1 is a schematic block diagram of a working situation of a three-dimensional printing apparatus according to an embodiment of the present disclosure. Referring to Figure 1, a three-dimensional printing apparatus 100 of the present embodiment is adapted to print a three-dimensional object in accordance with three-dimensional model information. Additionally, a host computer 200 is an apparatus having a computing function, for example, a computing apparatus, such as a laptop, a tablet computer, or a desktop computer. The present disclosure does not limit the types of host 200. The host computer 200 can edit and process a three-dimensional model of a three-dimensional object and transmit related three-dimensional model information to the three-dimensional printing apparatus 100, such that the three-dimensional printing apparatus 100 can print a three-dimensional object in accordance with the information in three-dimensional model. In the present embodiment, the three-dimensional model can be a three-dimensional digital image file, which can be built by a mainframe computer 200 by means of computer-aided design (computer-aided design, CAD), animation modeling software, or the like, and host 200 performs layer cut processing on the three-dimensional model to obtain three-dimensional model information associated with multi-layered objects, such that three-dimensional printing apparatus 100 can sequentially print each layer layer object. according to the three-dimensional model information that corresponds to the layer objects, so that it finally forms a complete three-dimensional object.

Fig. 2 is a schematic diagram of a three-dimensional printing apparatus according to an embodiment of the present disclosure. Referring to Figure 2, three-dimensional printing apparatus 100 includes a platform 110, a printing module 120, and a controller 130. A rectangular coordinate system is also provided herein to facilitate the description of related media and states of motion. of the same. Platform 110 includes a support surface S1, configured to support a three-dimensional object 80 in printing. The printing module 120 is arranged on top of the platform 110 and includes a fusing nozzle 121 and a feeding module 123. In the present embodiment, the feed module 123 is configured to feed a first forming material 20a and a second forming material 20b to the melt nozzle 121 in a period of filament extrusion, and the melt nozzle 121 is configured to melt the first forming material 20a having a first color and a second forming material 20b having a second color. The printing module 120 is configured to move along an XY plane and along a normal direction of the XY plane (one direction of a Z axis), such that the fusing nozzle 121 coats a third material 20c of formation on the support surface S1 of the platform 110. Specifically, the melt nozzle 121 extrudes the third formation material 20c generated by mixing the first formation material 20a and the second formation material 20b, such that the third material Formation 20c is cured in three-dimensional object 80 on platform 110.

Additionally, controller 130 is coupled to platform 110 and printing module 120, and can be configured to read three-dimensional model information provided by host 200, and control the overall operation of three-dimensional printing apparatus 100 in accordance with the information of three-dimensional model to print the three-dimensional object 80. For example, controller 130 may control a motion path of print module 120 in accordance with the three-dimensional digital model information. Controller 130, for example, is a device that has a computing function, for example, a central processing unit, a chipset, a microprocessor, or a built-in controller.

Additionally, controller 130 can control, according to three-dimensional model information, printing module 120 to move over platform 110, and control feeding module 123 to feed first forming material 20a and second material 20b forming at the melt die 121 in a filament extrusion period. The first forming material 20a and the second forming material 20b can be hot melt filaments suitable for making fused filaments, and are heated using the melt nozzle 121, such that the first forming material 20a and the Second forming material 20b which is conveyed to the melt nozzle 121 is melted into a fluid material in the molten state. In the present embodiment, the first forming material 20a has a first color, and the second forming material 20b has a second color. The first forming material 20a and the second forming material 20b which are in the molten state are mixed in a chamber of the melting nozzle 121, to generate the third forming material 20c having a third color. The melting nozzle 121 extrudes the third forming material 20c having the third color and being in a molten state, such that the third forming material extruded by the melting nozzle 121 is cured in the three-dimensional object 80 on the platform 110.

In this case, the third color is determined according to a ratio of a feed amount of the first forming material 20a to a feed amount of the second forming material 20b being fed into the melt nozzle 121. Using that, the first forming material / second forming material in wire form that can be measured in units of length is fed as an example, the amount of feed from the The first forming material 20a, for example, is 1.2 cm / min, and the feed amount of the second forming material 20b, for example, is 0.8 cm / min. That is, the feed module 123 feeds the first forming material 20a into the melt nozzle 121 at a rate of 1.2 cm / min, and feeds the second forming material 20b into the melt nozzle 121 at a rate of 0.8 cm / min.

A sum of a first feed ratio and a second feed ratio satisfies a preset percentage. Using that, the sum of the first feed ratio and the second feed ratio satisfies one hundred percent as an example, a total feed amount of the third forming material 20c extruded by the melt nozzle 121 is substantially equal to one sum of the feed amount of the first forming material 20a and the feed amount of the second forming material 20b. As used herein, a ratio of the feed amount of the first forming material 20a to a total feed amount of the melt nozzle 121 is referred to as the first feed ratio, and a ratio of the feed amount of the second material 20b of formation at the total feed amount of the melt nozzle 121 is referred to as the second feed ratio. For example, if the feed amount of the first forming material 20a is 1.2 cm / min, and the feed amount of the second forming material 20b is 0.8 cm / min, the first feed ratio of the first material 20a Forming is 60%, and the second feed ratio of the second forming material 20b is 40%. Therefore, because the third color is determined according to the ratio of the feed amount of the first forming material 20a to the feed amount of the second forming material 20b, the third color of the third forming material 20c also it can be considered to be determined according to the first feeding ratio of the first forming material 20a and the second feeding ratio of the second forming material 20b.

Fig. 3A and Fig. 3B are schematic diagrams of a fusion nozzle and a feed module according to an embodiment of the present disclosure. Referring to FIG. 3A first, in the present embodiment, the feed module 123 includes a material supply line L1 and a material supply line L2 which are connected to the melt nozzle 121, a first feed roll 123a, a second feed roll 123d, a passive roll 123b, and a passive roll 123c. In detail, the first feed roll 123a and the passive roll 123b are respectively provided on two opposite sides of the material supply line L1. In a filament extrusion period, the first feed roll 123a and the passive roll 123b together hold the second forming material 20b in the material supply line L1 and drive the second forming material 20b to advance along a transport direction D1, and the second feed roller 123d and the passive roller 123c together hold the first forming material 20a in the material supply line L2 and drive the first forming material 20a to advance along direction D1 Of transport. In other words, a motor (not shown) from the feed module 123 feeds the first forming material 20a and the second forming material 20b into the melt nozzle 121 by actuating the first feed roll 123a and the second feed roll 123d. feed into a first direction R1, and the melting nozzle 121 extrudes the third forming material 20c in the filament extrusion period.

In an exemplary embodiment, in a filament extrusion period, controller 130 can control a rotation speed of the first feed roll 123a according to the first feed ratio, and control a rotation speed of the second feed roll 123d according to the second feeding ratio.

Referring to FIG. 3B below, in the present embodiment, in a period of filament extrusion suspension, the first feed roll 123a and the passive roll 123b together hold the second forming material 20b in the material supply line L1 and drive the second forming material 20b to advance along a transport direction D2, and the second feed roll 123d and the passive roll 123c together hold the first forming material 20a in the material supply line L2 and drive the first forming material 20a to advance along the transport direction D2. In other words, the motor (not shown) of the feed module 123 retracts the first forming material 20a and the second forming material 20b along a direction away from the melting nozzle 121 upon actuation of the first roller Feed 123a and the second feed roll 123d to a second direction R2.

Based on the description of Fig. 2, Fig. 3A, and Fig. 3B, in an exemplary embodiment, in the filament extrusion suspension period of the printing module 120, the controller 130 can determine the first amount of back extraction according to the first feed ratio of the first forming material 20a, and determining the second back extraction amount according to the second feeding ratio of the second forming material 20b. The first amount of back extraction and the second amount of back extraction above can be indicated and measured in units of length. For example, the description in Figure 3B continues; when the first back extraction amount is 6 mm, the controller 130 controls the feed module 123 to back extract the first forming material 20a by 6 mm along the transport direction D2. That is, the first back extraction amount and the second back extraction amount are determined individually according to the corresponding feed ratios.

On such a basis, in a period of filament extrusion suspension, controller 130 can control feed module 123 to back-extract the first forming material 20a according to the first amount of back extraction along the direction away from the fusion nozzle 121. Meanwhile, in the filament extrusion suspension period, the controller 130 can control the feed module 123 to back-extract the second forming material 20b according to the second amount of back-extraction along the direction away from the fusion nozzle 121. In an exemplary embodiment, the first backflush amount increases along with an increase in the first feed ratio, and the first backflush amount decreases along with a decrease in the first feed ratio. Similarly, the second back extraction amount increases along with an increase in the second feed ratio, and the second back extraction amount decreases along with a decrease in the second feed ratio. In this way, in the filament extrusion suspension period, the three-dimensional printing apparatus 100 can remove the first forming material 20a and the second forming material 20b from the melt nozzle 121, thereby preventing materials melt forming drip onto platform 110 from the melt nozzle 121 in an extrusion stop period.

In order to further describe how controller 130 controls power module 123, the present disclosure is described below with reference to one embodiment. Fig. 4 is a schematic diagram of a method for controlling a three-dimensional printing apparatus in accordance with an embodiment of the present disclosure. The method of the present embodiment is adapted to the three-dimensional printing apparatus 100 of FIG. 2, and the detailed steps of a nozzle temperature setting procedure of the present embodiment are described below with reference to each medium in the apparatus 100 of three-dimensional printing.

In step S401, when a three-dimensional printing apparatus 100 operates in a filament extrusion period, a controller 130 controls a feed module 123 to feed a first forming material 20a and a second forming material 20b to a nozzle 121 of melting such that it operates the melting nozzle 121 to extrude a third forming material 20c generated by mixing the first forming material 20a and the second forming material 20b. In step S402, controller 130 determines a first back extraction amount and a second back extraction amount according to a first feed ratio of the first forming material 20a and a second feed ratio of the second forming material 20b. It should be noted that because a sum of the first feed ratio and the second feed ratio satisfies a preset percentage, the first feed ratio has a correspondence with the second feed ratio. In other words, there is also a preset ratio from the first feed ratio to the second feed ratio. In one embodiment, controller 130 can obtain the first feed ratio and the second feed ratio according to the preset percentage. Therefore, in one embodiment, controller 130 can also determine the first back draw amount and the second back pull amount according to the preset percentage and the preset ratio of the first feed ratio to the second feed ratio. In step S403, when the three-dimensional printing apparatus 100 operates in a period of filament extrusion suspension, the controller 130 controls the feed module 123 to back-extract the first forming material 20a according to the first amount of back-extraction thereto. along a direction away from the fusion nozzle 121, and controls the feed module 123 to back extract the second forming material 20b according to the second amount of back extraction along the direction away from the nozzle 121 , and actuates the fusing nozzle 121 to leave a final print location.

It should be noted that, in the filament extrusion period, the melt nozzle 121 extrudes the third melt forming material 20c onto a platform to establish a three-dimensional object 80, and in the filament extrusion suspension period, the nozzle Melting 121 ceases to extrude the third forming material 20c in the molten state. A period in which the print module 120 moves from a print end location to a print start location is the filament extrusion suspension period. More specifically, referring to Figure 2, after the printing module 120 completes a printing action of a first layer layer object 80b, the printing module 120 first ascends along a Z axis, and then it moves along an XY plane to a printing start location of a second layer layer cut object 80a, and then extrudes the third forming material 20c to print the second layer layer object 80a. After the printing module 120 completes a printing action of the second layer layer cutting object 80a, the printing module 120 first moves along the XY plane to a printing start location of the cutting object 80c of the second layer layer, and then extrudes the third forming material 20c to print the second layer layer cut object 80c. The above filament extrusion suspension period may be a period in which the printing module 120 moves from the final printing location of the first layer layer cutting object 80b to the printing starting location of the first layer 80a object. second layer layer cut. Or, the previous filament extrusion suspension period may be a period in which the printing module 120 moves from the final printing location of the second layer layer object 80a to the printing start location of the second layer object 80c. second layer layer.

In an exemplary embodiment, when the first feed ratio of the first forming material 20a is the same as the second feed ratio of the second forming material 20b, controller 130 sets the first amount of back extraction of the first forming material 20a so that is equal to the second back-extraction amount of the second forming material 20b. When the first feed ratio of the first forming material 20a is different from the second feed ratio of the second Forming material 20b, controller 130 determines that the first amount of back extraction of the first forming material 20a is different from the second amount of back extraction of the second forming material 20b. Thus, in the filament extrusion suspension period, the three-dimensional printing apparatus 100 of the present disclosure can prevent the third forming material 20c from overflowing from the melting nozzle 121 and dripping onto a platform 110, and maintaining the consistency of a third color of the third forming material 20c.

The following further describes how the controller respectively determines the first back extraction amount and the second back extraction amount. In an exemplary embodiment, controller 130 can calculate the first back extraction amount according to the first feed ratio using an interpolation procedure and a first reference interval. Similarly, controller 130 can calculate the second back extraction amount according to the second feed ratio using the interpolation procedure and the first reference interval, where the first reference interval is between 0 and a first reference value. For example, Figure 5A is an exemplary schematic diagram of back extraction amount determination in accordance with one embodiment of the present disclosure. Referring to Figure 5A, the first back extraction amount and the second back extraction amount are values within a first reference interval rag1, and the first reference interval rag1 is between 0 and a first reference value Refl. The first reference value Refl can be set according to actual application situations, and is not limited in the present disclosure. In general, the first reference value Refl is an ideal back extraction amount obtained after experiments when a feed ratio of a forming material (i.e. the first forming material or the second forming material) is one hundred percent .

Continuing with reference to FIG. 5A, because controller 130 calculates the first back extraction amount and the second back extraction amount within the first reference interval rag1 according to the interpolation procedure, back extraction amount and feed ratio of the forming material (ie, the first forming material or the second forming material) can be indicated as a linear relationship 51 in Figure 5A. Additionally, if the first feed ratio is zero percent (0%), controller 130 determines that the first back draw amount is 0 within the first reference range rag1. If the first feed ratio is one hundred percent (100%), controller 130 determines that the first back draw amount is the first Refl reference value within the first reference range. Similarly, if the second feed ratio is 0%, controller 130 determines that the second back extraction amount is 0 within the first reference range rag1. If the second feed ratio is one hundred percent (100%), controller 130 determines that the second back extraction amount is the first Refl reference value within the first reference range. Furthermore, continuing with reference to FIG. 5A, if the first feed ratio is X1% and the second feed ratio is (100-X1)%, controller 130 can determine that the first amount of back extraction is equal to Ref3 and the second amount of back extraction is equal to Ref4 according to the interpolation procedure corresponding to linear relationship 51, the first feed ratio, and the second feed ratio.

Furthermore, in an exemplary embodiment, when the first feed ratio is the same as the second feed ratio, controller 130 can directly set the first back draw amount and the second back pull amount to be a second reference value. When the first feed ratio is different from the second feed ratio, controller 130 calculates the first back extraction amount according to the first feed ratio using the interpolation procedure and one of a second reference interval and a third interval of reference, and calculates the second back extraction amount according to the second feed ratio using the interpolation procedure and the other one of the second reference interval and the third reference interval. It should be noted that controller 130 can obtain the second reference interval and the third reference interval according to the first reference value and the second reference value. The first reference value and the second reference value can be set according to actual application situations, and are not limited in the present disclosure. In general, the first reference value is an ideal back extraction amount obtained after experiments when a feed ratio of a forming material (i.e. the first forming material or the second forming material) is one hundred percent, and the second reference value is an ideal back extraction amount obtained after experiments when the feed ratio of the forming material (ie, the first forming material or the second forming material) is fifty percent.

For example, FIG. 5B is an exemplary schematic diagram of back extraction amount determination according to one embodiment of the present disclosure. Referring to FIG. 5B, controller 130 obtains a second reference interval rag2 and a third reference interval rag3 according to the first reference value Refl and a second reference value Ref2. The second reference interval rag2 is between 0 and the second reference value Ref2; the third reference interval rag3 is between the second reference value Ref2 and the first reference value Refl, where the first reference value Refl is greater than the second reference value Ref2.

Continuing with reference to FIG. 5B, because controller 130 calculates the first back extraction amount and the second back extraction amount within the second reference interval rag2 according to the interpolation procedure, back extraction amount and feed ratio of the material of Formation (ie, the first formation material or the second formation material) can be indicated as a linear relationship 52 and a linear relationship 53 in Figure 5B. If the first feed ratio is 0%, controller 130 determines that the first back draw amount is 0 within the second reference range rag2. If the first feed ratio is 50%, controller 130 determines that the first back extraction amount is the second reference value Ref2 used to distinguish the second reference interval rag2 from the third reference interval rag3. If the first feed ratio is 100%, controller 130 determines that the first back extraction amount is the first Refl reference value within the third reference interval rag3.

Furthermore, continuing with reference to FIG. 5B, if the first feed ratio is X2% and the second feed ratio is (100-X2)%, controller 130 can calculate that the first back extraction amount equals Ref6 according with the first feeding ratio using the interpolation procedure and the second reference interval rag2. Furthermore, controller 130 can calculate that the second back extraction amount equals Ref5 according to the second feed ratio using the interpolation procedure and the third reference interval rag3. If the optimal setting received by controller 130 is assuming that the first reference value Refl is equal to 12mm and the second reference value Ref2 is equal to 8mm, controller 130 can determine the first amount of back extraction and the second amount back extraction according to the following Table (1) by means of the interpolation procedure. However, Table (1) is merely an embodiment, and is not intended to limit the present disclosure.

Table 1)

Based on the foregoing, in the embodiments of the present disclosure, a first amount of back extraction of a first forming material is determined according to a first feed ratio of the first forming material, and a second amount of back extraction is determined from a second forming material according to a second feed ratio of the second forming material. In a period in which the printing module moves to a next printing start point, the feed module back-pulls the first forming material according to the first back-pulling amount along a direction away from the fusion nozzle and back-extracts the second forming material according to the second amount of back-extraction along the direction away from the fusion nozzle. In this way, the three-dimensional printing apparatus of the present disclosure can prevent melt forming materials from overflowing from the melting nozzle and dripping onto the platform, and maintain the consistency of a harmonious color generated by mixing multiple printing materials. formation in such a way that it prevents the three-dimensional printing apparatus from printing a three-dimensional printed object with a non-uniform color.

Claims (10)

1. A three-dimensional printing apparatus (100), comprising: a printing module (120), comprising: a melting nozzle (121) configured to melt a first forming material (20a) having a first color and a second forming material (20b) having a second color; and a feed module (123) configured to feed the first forming material (20a) and the second forming material (20b) to the melt die in a filament extrusion period; and characterized in that said three-dimensional printing apparatus further comprises: a controller (130), coupled to the printing module (120), and configured to: determine a first amount of back extraction and a second amount of back extraction according to a first feed ratio of the first forming material (20a) and a second feed ratio of the second forming material (20b) into a filament extrusion suspension period of the printing module (120); controlling the feed module (123) to back-extract the first forming material (20a) in accordance with the first amount of back-extraction along a direction (D2) away from the melting nozzle (121) in the period of filament extrusion slurry, and controlling the feed module (123) to back-extract the second forming material (20b) according to the second amount of back-extraction along the direction (D2) away from the nozzle (121 ) melting in the filament extrusion suspension period, in which a sum of the first feed ratio and the second feed ratio satisfies a pre-established percentage, wherein said first feed ratio is the ratio of the feed amount of the first forming material to a total feed amount of the melt die and said second feed amount is the ratio of the feed amount of the second forming material. formation at the total feed amount of the fusion nozzle. The three-dimensional printing apparatus (100) according to claim 1, wherein the melting nozzle (121) extrudes a third forming material (20c) generated by mixing the first forming material (20a) and the second forming material (20b) such that the third forming material (20c) is cured into a three-dimensional object (80) on a platform (110); the third forming material (20c) has a third color, and the third color is determined according to the first feed ratio and the second feed ratio. The three-dimensional printing apparatus (100) according to claim 1 or 2, wherein the feed module (123) comprises a first feed roll (123a) and a second feed roll (123d); the feed module (123) feeds the first forming material (20a) and the second forming material (20b) into the melting nozzle (121) by actuating the first feed roll (123a) and the second roll (123d) feed to rotate to a first direction (R1); and the feed module (123) back-extracts the first forming material (20a) and the second forming material (20b) along the direction (D2) away from the melting nozzle (121) by actuating the first feed roll (123a) and the second feed roll (123d) to a second direction (R2). The three-dimensional printing apparatus (100) according to claim 3, wherein the controller (130) controls a rotational speed of the first feed roll (123a) according to the first feed ratio, and controls a rotation speed of the second feed roll (123d) according to the second feed ratio. The three-dimensional printing apparatus (100) according to one of the preceding claims, wherein, if the first feed ratio is the same as the second feed ratio, the first back extraction amount is the same as the second back extraction amount; and if the first feed ratio is different from the second feed ratio, the first back extraction amount is different from the second back extraction amount. 6. The three-dimensional printing apparatus (100) according to claim 5, wherein the controller (130) calculates the first back extraction amount according to the first feed ratio using an interpolation procedure and a first reference interval (rag1); controller 130 calculates the second back extraction amount according to the second feed ratio using the interpolation procedure and the first reference interval (rag1), where the first reference interval (rag1) is between 0 and a first reference value. The three-dimensional printing apparatus (100) according to claim 6, wherein, if the first feed ratio is zero percent, the first back extraction amount is 0 within the first reference range (rag1), and if the first feed ratio is one hundred percent, the first back draw amount is the first reference value within the first reference range (rag1). The three-dimensional printing apparatus (100) according to one of claims 5-7, wherein the controller (130) obtains a second reference interval (rag2) and a third reference interval (rag3) according to a first reference value and a second reference value; the second reference interval (rag2) is between 0 and the second reference value; the third reference interval (rag3) is between the second reference value and the first reference value, and the first reference value is greater than the second reference value; wherein, if the first feed ratio is the same as the second feed ratio, the controller (130) directly sets the first back draw amount and the second back pull amount as the second reference value; and wherein if the first feed ratio is different from the second feed ratio, the controller 130 calculates the first back extraction amount according to the first feed ratio using an interpolation procedure and one of the second reference interval ( rag2) and the third reference interval (rag3), and calculates the second back extraction amount according to the second feed ratio using the interpolation procedure and the other one of the second reference interval (rag2) and the third reference interval (rag3). 9. The three-dimensional printing apparatus (100) according to claim 8, wherein if the first feed ratio is zero percent, the first back draw amount is 0 within the second reference range (rag2); if the first feed ratio is fifty percent, the first back extraction amount is the second reference value used to distinguish the second reference interval (rag2) from the third reference interval (rag3); and if the first feed ratio is one hundred percent, the first back extraction amount is the first reference value within the third reference range (rag3). 10. A method of controlling a three-dimensional printing apparatus (100), wherein the three-dimensional printing apparatus (100) comprises a melting nozzle (121) and a feed module (123), and the method comprises: when operating in a filament extrusion period, controlling (S401) the feed module (123) to feed a first forming material (20a) and a second forming material (20b) to the melting nozzle (121), such that it operates the melting nozzle (121) to extrude a third forming material (20c) generated by mixing the first forming material (20a) and the second forming material (20b); Said procedure characterized in that it further comprises: determining (S402) a first back extraction amount and a second back extraction amount according to a first feed ratio of the first forming material (20a) and a second feed ratio of the second forming material (20b); and when operating in a filament extrusion suspension period, control (S403) the feed module (123) to back-extract the first forming material (20a) according to the first amount of back-extraction along one direction (D2 ) moving away from the melting nozzle (121), and controlling the feed module (123) to back-extract the second forming material (20b) according to the second amount of back-extraction along direction (D2) which moves away from the fusing nozzle (121), and actuating the fusing nozzle (121) to leave a final print location, where a sum of the first feed ratio and the second feed ratio satisfies a preset percentage, wherein said first feed ratio is the ratio of the feed amount of the first forming material to a total feed amount of the melt die and said second feed amount is the ratio of the feed amount of the second forming material. formation at the total feed amount of the fusion nozzle.